Selena and her friends went out to dinner. The bill came to $56.25. If the the tax rate is 7.5 percent and they left a 15 percent tip. How much money did they spend at the restaurant ?

Depends - do they tip on the whole bill? Most folks do. In that case, they spent

$56.25 * 1.15

if the tax is included in the bill, as is usually the case.

You are right

I don't get it

c'mon. You get a bill for $56.25

You tip 15%, which is 56.25 * .15

You add that to the bill, so your final amount is

56.25 + 56.15 * .15 = 56.25(1+.15)

I interpret this problem differently.

When the bill is presented to me, I see the cost of the meal plus the tax.

56.25 * 1.075 = $60.47

Then I'd figure the tip on that amount.

60.47 * 0.15 = $9.07

60.47 + 9.07 = 69.54

Yeah, that's the problem when the assumptions aren't explained.

Another way would be to assume the bill included the tax, so the actual meal only cost

56.25/1.075, and the tip was calculated on that basis.

There'd be no reason to even mention the tax if it weren't to be considered in some way, so I specifically asked about it, and got no further information.

To calculate how much money Selena and her friends spent at the restaurant, we need to consider the bill amount, the tax rate, and the tip.

Step 1: Calculate the tax amount:
Tax amount = Bill amount × Tax rate
Tax amount = $56.25 × 7.5% (or 0.075)
Tax amount = $4.22

Step 2: Calculate the tip amount:
Tip amount = Bill amount × Tip rate
Tip amount = $56.25 × 15% (or 0.15)
Tip amount = $8.44

Step 3: Add the bill amount, tax amount, and tip amount to get the total amount spent:
Total amount spent = Bill amount + Tax amount + Tip amount
Total amount spent = $56.25 + $4.22 + $8.44
Total amount spent = $68.91

Therefore, Selena and her friends spent a total of $68.91 at the restaurant.